Abstract: The capabilities of the |effective indenter method| with respect to the characterisation of porous xerogel thin films have been investigated using samples with porosities ranging from 43% to 57%. Young|s modulus of the samples was decreasing from 2.67 GPa to 0.83 GPa with growing porosity. Yield strength was determined using spherical indentation data. With a larger indenter (R = 48 μm) the |effective indenter method| could be directly applied while for a smaller one (R = 4.2 μm) the |effective indenter extrapolation method| had to be utilised to account for the larger amount of plastic deformation. Both approaches delivered the same yield strength decreasing from (140 ± 5) MPa to (75 ± 3) MPa with increasing porosity.